The invention adapted to affect the transportation of sperm in the uterine tube may help women to avoid pregnancy by preventing the sperm to reach the egg by preventing the sperm to reach the egg for a predetermined amount of time, thus affect the flow of the sperm. The lifetime of a sperm is normally 3-5 days. Furthermore the transportation of egg takes so long time in the uterine tube that any egg reaching the proximal part of the uterine tube is most likely not viable any more. The invention furthermore in an alternative object promotes sperms to reach the uterine tube and the egg increasing the likelihood for pregnancy.
Conceptive drugs may cause blood clots and other serious complications. A safer more permanent but still adjustable device has an important role to fill.